Boat propelling apparatus



Sept. 13, 1938. H. FROMM 2,130,125

BOAT PROPELLING APPARATUS Filed April 2, 1937 Ha a F a2. JU /\37 Q P i?) a I J 4.3

a4 3M HARRY E. FRO/VIM.

Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE BOAT PBOPELLING APPARATUS Application April 2, 1937, Serial No. 134,548

3 Claims.

This invention relates to an improved motor boat power transmitting assembly.

More particularly, the invention pertains to improvements in V transmission drives for boat 5 propeller shafts.

The use of a V type propeller drive transmitting mechanism in a motor boat is particularly advantageous when it is desired to position the power plant of the boat at a rearward location therein. This can be accomplished by arranging an internal combustion, or other prime mover, engine with the driving end of its crank shaft disposed forwardly and providing the customary clutch and reverse gear mechanism on the front end of the engine. The propeller shaft of the boat is then disposed at an inclination and in V relationship with respect to the engine crank shaft with its longitudinal axis intersecting the crank shaft axis at a location in advance of the 20 power unit, a pair of bevel gears being provided at the front end of the power unit for transmitting the drive from the line of one of the converging axes to the other.

Heretofore, it has been the practice to provide a coupling between the propeller shaft and the bevel gearing at a location rearwardly of the latter, thus necessitating the placement of the power unit further forwardly than would otherwise be required in order to accommodate the coupling structure. This practice has also rendered difficult the attachment and detachment of propeller shafts for inspection and repair and resulted in locating of the coupling in an inaccessible space. In some instances, it has been necessary to mount the engine at a higher elevation in a boat than would otherwise have been required, in order to accommodate such a coupling element and to facilitate access thereto.

One of the main objects of the invention is to provide a unitary reverse gear housing, V drive gear housing and propeller shaft coupling which can be accommodated in relatively little space forward of an engine and which facilitates placement of the engine at the extreme rear end portion of a boat.

Another object of the invention is the provision of a coupling for connecting a propeller shaft of a boat to the drive gearing thereof which is adapted to be positioned forwardly of the propeller drive transmitting gearing so as to reduce the distance requirement between the propeller and such gearing and thereby enable placement of the engine at a further rearwardly position in a boat than is customarily permissible.

A further object of the invention is the provision of a coupling structure in a motor boat power plant and propeller drive assembly which is located at the forwardmost extremity of the assembly and unobstructed by other parts thereof or otherwise so disposed as to require disassembly of the unit in order to couple and uncouple the propeller shaft.

An illustrative embodiment of the invention is shown in the accompanying drawing, in which:

Fig. 1 is a side elevational View of a motor boat equipped with the improved propeller shaft driving mechanism showing the boat partly in section and having portions removed to disclose the underlying structure.

Fig. 2 is an enlarged vertical sectional view of propeller drive transmitting mechanism embodying the invention.

In the form of the invention illustrated in the drawing, a motor boat, generally designated by the numeral I0, is provided with a stern power plant compartment H in which is mounted an internal combustion engine [2 having attached thereto clutch and reverse gear transmission housings M and [3 respectively. The engine i2 is preferably arranged centrally of the boat with its crank shaft axis extending longitudinally thereof and the end of the engine from which the drive is taken is directed forwardly. The engine unit is disposed as far to the stern of the boat as the structure thereof will permit.

Provided in the hull if: of the boat is a propeller shaft receiving opening it with which a propeller shaft bearing and sealing sleeve ll is associated. A propeller shaft l8 journalled in the bearing I7 is disposed below the engine l2 and arranged at an inclination with respect to the axis of the crank shaft so as to provide a V type drive. Provided on the external end of the propeller shaft it is a propeller It.

The reverse gear housing it has a transversely extending partition 2!) intermediate its ends in which is provided an opening 2! for receiving a bearing member 22 in which a transmission shaft 23 of the reverse gear mechanism (not shown) is journalled. The forward end portion of the housing i3 is provided with a downwardly projecting extension 24 having a rear end wall portion 25 in which is formed an opening 25 for receiving a bearing member 27. The forward wall of the extension 2 3 of the housing I3 is provided with an opening 28 which is substantially larger than the opening 2% and which is normally closed by a bearing carrying cover member 29. The cover member, generally designated by the numeral 28, comprises a central tubular portion 30 detachably secured to the extension 24 of the housing 13 by bolts 36.

Provided on the forward end portion of the transmission shaft 23 is a bevel gear 31 having teeth meshed with the teeth of a bevel gear, generally designated by the numeral 38, which includes oppositely extending tubular hub portions 39 and 40, respectively. The rearwardly extending tubular hub portion 39 is journalled in the bearing member 21 mounted in the rear wall of the housing extension 24 and the forwardly extending tubular hub portion 40 of the gear 38, which is substantially longer than the hub portion 39 thereof, extends through the tubular portion 38 of the cover member 29 substantially in advance of the transmission housing extension 24. An intermediate portion of the tubular hub portion 40 of the gear 38 is rotatably supported by the bearing member 33.

The propeller shaft I8 extends through the central passage 4! of the gear 38 and its tubular hub portions and projections beyond the forward extremity of the hub portion 40 of the gear, the gear 38 being disposed at an inclination corresponding to the inclination of the propeller shaft l8 in order to accommodate positioning thereof in the relationship illustrated in Fig. 1. The for- Fig. 2. The collar 43 has a radially extending flange 44 which is detachably connected by bolts 45 to a radial flange 46 of a collar 41 which is splined, as indicated at 48, on the external front end portion of the propeller shaft I8. A nut 49 threaded on the front end portion of the hub portion 40 of the gear 38 detachably secures the collar 43 of the coupling 42 against axial displacement of the hub portion 48 from the gear 38.

By providing a coupling member 42 at a location adjacent the converging end portions of the axes of the transmission shaft 23 and propeller shaft l8 and forwardly of the transmission housing l3 and its extension 24, the requirement of space between the transmission housing extension 24 and the propeller IS in the line of the propeller shaft for the accommodation of the cou pling, is rendered unnecessary. It is therefore possible to position the power plant of the boat further rearwardly than would otherwise be permissible. The provision of the coupling element in an unobstructed space at the forward extremity of the power unit facilitates convenient attachment and detachment of the gear 38 and propeller shaft and accommodates removal of the propeller shaft 18 in a forward direction into the interior of the boat when the propeller I9 is detached. The combined and unitary reverse gear housing and propeller shaft gearing casing provided by the extension 24 of the housing 13 presents a compact structure which may also be combined with the clutch housing l4 and accommodated in a relatively small space within the boat.

Although but one specific embodiment of the invention is herein shown and described, it will be understood that various changes in the size,

,shape and arrangement of parts may be made 'without departing from the spirit of my invention.

I claim:

1. A propeller power transmitting apparatus for boats in which the engine is mounted in the stern, said apparatus comprising a gear housing attached to and forming an extension of the forward end of the frame of said engine, a bevel drive gear journaled in the upper portion of said housing for rotation by said engine, a bevel driven gear meshing with said drive gear and journalled in the lower portion of said housing, said driven gear having a bore extending axially therethrough, a propeller shaft extending loosely through said bore rearwardly and downwardly below said engine and having a propeller mounted upon its rearward end, a detachable connection between said propeller shaft and said driven gear positioned forwardly of said driven gear, said detachable connection including a member secured to said drivenv gear, a member secured to said shaft and means for positively connecting said members together, the portion of said propeller shaft between said driven gear and the rearward end of said propeller shaft being of smaller diameter than said bore, and said housing having an aperture in alignment with said bore whereby said propeller shaft can be withdrawn forwardly through said driven gear when detached therefrom.

2. A propeller power transmitting apparatus for boats in which the engine is mounted in the stern, said apparatus comprising a gear housing attached to and forming an extension of the forward end of the frame of said engine, a bevel drive gear journaled in the upper portion of said housing for rotation by said engine, a bevel driven gear meshing with said drive gear and journaled in the lower portion of said housing, said driven gear having a bore extending axially therethrough, a propeller shaft extending loosely through said bore rearwardly and downwardly below said engine and having a propeller mounted upon its rearward end, a detachable connection between said propeller shaft and said driven gear positioned forwardly of said driven gear, said detachable connection including a flange member secured to said driven gear, a flange member secured to said shaft and means for positively connecting said members together, the portion of said propeller shaft between said driven gear and the rearward end of said propeller shaft being of smaller diameter than said bore and said housing having an aperture in alignment with said bore whereby said propeller shaft can be withdrawn forwardly through said driven gear when detached therefrom.

3. A propeller power transmitting apparatus for boats in which the engine is mounted in the stern, said apparatus comprising a gear housing attached to and forming an extension of the forward end of the frame of said engine, a bevel drive gear journaled in the upper portion of said housing for rotation by said engine, a bevel driven gear meshing with said drive gear and positioned in the lower portion of said housing, said driven gear being provided with concentric sleeve portions extending forwardly and rearwardly of said gear, the rearward sleeve portion being journaled in said housing, said housing having an opening in its forward end, a cover member for said opening having an aperture in which said forwardly extending sleeve portion is journaled and through which said forwardly extending sleeve portion projects, said driven gear and sleeve portions having a bore extending axially therethrough, a propeller shaft extending loosely through said bore rearwardly and downwardly below said engine and having a propeller mounted upon its rearward end, a detachable connection between the forward end of said forwardly extending sleeve portion and the forward end of said shaft for positively connecting said driven gear and shaft together, the portion of said propeller shaft between said driven gear and the rearward end of said propeller shaft being of smaller diameter than said bore, whereby said propeller shaft can be withdrawn forwardly through said driven gear without removing said cover member when said shaft is detached from said driven gear.

HARRY E. FROMM. 

